The leader of a self-styled Russian Christian religious group detained as a suspect in a high-profile arson attack, has been placed under arrest for one month, Russian news agencies reported on September 23.

Aleksandr Kalinin, the leader of an organization that calls itself Christian State-Holy Rus, was detained on September 20 as a suspect in the September 11 arson attack on cars outside the Moscow office of lawyers for the director of Matilda, an upcoming film that has drawn sharp criticism from radical Russian Orthodox and monarchist fringe groups.

"At the request of the investigator, Kalinin has been remanded in custody until November 22," a spokesperson for Moscow's Taganksy court was quoted as saying.

Earlier on September 23, Russia's Interior Ministry said it had launched criminal proceedings into threats to owners of cinema chains planning to screen Matilda.

The movie, directed by Aleksei Uchitel, is based on an early romantic liaison of Russia's last tsar, Nicholas II.

The Culture Ministry approved the film for release in July and it is scheduled to open nationwide next month (October 26).

Critics of the movie say it besmirches the memory of Nicholas, who was killed by the Bolsheviks in 1918 and was canonized by the Russian Orthodox Church together with his family in 2000.

A letter signed by Christian State-Holy Rus and distributed in January said that members across Russia were prepared to sacrifice their lives for its “true Orthodox Christian path” and that showing Matilda could lead to bloodshed and “civil war.”

Following several attacks appearing to target Uchitel and his film, Russia's biggest cinema chain said on September 12 it would not show Matilda, citing concerns for the safety of moviegoers.

The announcement came a day after a September 11 arson attack in which authorities say masked men torched two cars near the office of Uchitel’s lawyers and left leaflets that said "To Burn for Matilda."